My name is Fei. I'm 33 and I live in Texas. I'm a very inexperienced builder. A lot people said the GTM kit isn't beginner friendly at all. But I enjoy being hands-on and I love performance cars, so I said **** it and pulled the trigger. I took delivery of GTM#534 around February 2022 (I made a post about it last year saying the delivery driver told me it was the last one). I've been working on it on and off, mostly during the winter times when my garage feels more comfortable than an oven.
I've been reading you guys' post pretty much word-for-word for the past 2-3 years. So, I decided it would be a good idea to post here about my progress. Everything I'm posting will be my first time doing it. Also, to make the "beginner experience" worse, I got a C6 donor instead of a C5. I feel like I possibly shot myself in the foot with this decision but I'm pretty optimistic that I'll eventually make it work (with a ton of research/modifications, of course).
I've seen a lot of yall's build and they're pretty amazing. If the things I post looks like I have no idea what the hell I'm doing, then you're probably right. So, please feel free to offer some pointers. I'll try to be as detailed as I can with my posts/replies. I'm currently at work. I'll start posting later when I'm at home. Thanks!
Fei
Last edited by ohmygosuness; 02-07-2023 at 01:34 PM.
Welcome aboard! Looking forward to seeing your progress...
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Hi Shane. Thanks!
I believe I still owe you some dimensions for the location of the shifter (if I remember correctly). I know it's been a while but it's always in the back of my head.
Yes.....I was looking thru my orders spreadsheet the other day and saw that I still showed that I owe you that plate. Whenever you're ready, just let me know.
That C6 steering column sure looks like a whole different beast than the C5!
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
IMG_20220208_181349_01[1].jpg
I've worked on the build very little since delivery, but a lot more last few months. The only things I have on it so far is the suspension, C6 steering column, 3 reservoirs.
C6 front suspension works on the GTM. Rear upper control arms don't work.
C6 steering column needs a little adjustment. I grinded off a lot of material for it to fit. steering3.jpg steering2.jpg steering1.jpg
I have the c6 corvette sitting next to the GTM. Taking it apart piece by piece as I put them into the GTM. Engine will be a stock ls2 with 65k miles. IMG_20221211_012016_965[1].jpg
Cleaned every piston from carbon build-up. Got all new gaskets/piston rings, gapped all the piston rings, honed each cylinder, etc clean pistons.jpg dirty pistons.jpg honed cylinders.jpg
While uploading these pictures, I came to a realization that I've spent more time prepping the engine than actually installing parts onto the GTM. But I'm at the final stages of putting the engine together. Just waiting for the paint to dry on the cylinder heads before re-assembling the engine.
Looking forward to the posts!! We'll gladly let you know if something is wrong LOL . On a serious note, the recommendations and pointers from the group are pretty solid, so feel free to ask away.
Looking forward to the posts!! We'll gladly let you know if something is wrong LOL . On a serious note, the recommendations and pointers from the group are pretty solid, so feel free to ask away.
Hi shoeless. I like what you did with your build! I've been following it carefully as I'm building mine. Mine's just not as detailed
Here's another thing from the C6 that don't fit as good as C5 for the GTM - the Gen IV LS valley cover. I grinded off that big pipe sticking above the valley cover to clear the throttle body. Still trying to figure out how I should cap off that hole. I'm wondering if a bolt will do the trick? valley cover.jpg
Here is the part I got to relocate the oil pressure sender. Anyone has a recommendation on which sensor I should get? oil presser sender.jpg
Thanks for the shot down the thread bore. Unfortunately if it does not have an internal flair, which it looks like it does not, then the direct tube and nut option will not work. I took a picture of what we have, which is all banjos, but am having issues sharing the photo. The good news is that the banjo fitting should just work with no mods on what you have there. Simply use what I linked to, along with the properly sized and threaded banjo bolt and then put the tube and flair nut directly on the flared end of the banjo fitting.
As for the oil pressure sender, you need to use the one that comes with the oil pressure gauge in the kit. If that block you have above the filter is to relocate the OEM sensor, it probably won't work for the gauge sender as the gauge sender is 1/8" NPT and the OEM sender is....I believe a straight metric thread with a crush washer? For the gauge sender, I normally take the OEM cast aluminum bypass piece and drill and tap it to 1/8" NPT.....
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
As for the oil pressure sender, you need to use the one that comes with the oil pressure gauge in the kit. If that block you have above the filter is to relocate the OEM sensor, it probably won't work for the gauge sender as the gauge sender is 1/8" NPT and the OEM sender is....I believe a straight metric thread with a crush washer? For the gauge sender, I normally take the OEM cast aluminum bypass piece and drill and tap it to 1/8" NPT.....
Drilling through the OEM cast aluminum piece is a good idea. I think I should have done that instead...
As for the relocator I bought, I do believe they sell an adaptor to 1/8" NPT. But I'm not sure if the transducer will be able to mount directly above it after using the adaptor. I think i may have to get one that's angled.
As for the hole on the valley cover, would it work if I just fill it up with some metal filler/epoxy?
Last edited by ohmygosuness; 02-13-2023 at 03:07 PM.
As for the hole on the valley cover, would it work if I just fill it up with some metal filler/epoxy?
As long as the epoxy you use is completely unaffected by oil and heat and you create something inside the hole for it to hold to....like get a dremel down in the hole and grind some grooves into the aluminum so that the epoxy is not just a smooth sided plug that could pop out under pressure......that might work?
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
I wouldn't risk it. Tap the hole and fill it with a screw in plug.
THIS.
If you want to make it permanent use epoxy on the threads.
Are you sure you have to remove the sender cast piece? I seem to recall I did this the first time I did a build and flipped the intake around. Then on a second engine I recall just trimming the intake manifold to clear the casting and using a plug in it. Yes you still have to relocate the sensor, but no cutting, tapping/welding of the valley cover is needed...IIRC. I haven't done a flipped intake in a long time though.
There are also available valley covers with the sensor blocked off...
The oil pressure boss on the LS3 is really tall......no way to avoid cutting it off. You can see in the top photo here just how far it holds the flipped intake up off the heads:
Even with it cut down so it only sticks up an 1/8" or 3/16", you may still need to trim a bit of the plastic webbing from the bottom of the intake to clear it.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Sorry to send you down a rabbit hole. I'll buy the fittings from you if you like. As you can see, they are what we use.
Now back to the issue. The problem I see with your proposed solution is that I believe the fitting you are using is pipe thread and you have it screwed into straight threads on the MC. I don't believe this will work. I have seen others connect up the proper way so I know it is doable. Too bad none of them have provided any pictures or insight.
Have you spoken with anyone at ANPlumbing.com? One of the reasons I use that vendor is because they have people there that will work with you and get you what you need. Prices are pretty close to Summit and Jegs but their searchability is much better. Maybe a lower profile banjo/bolt will work...maybe not, but it might be worth a phone call to ask what they have available?
Then, of course, there is always frame member modification...if you are willing and able. I seem to remember a small modification was done on the other setups I saw with the tubes coming out the front.
Sorry to send you down a rabbit hole. I'll buy the fittings from you if you like. As you can see, they are what we use.
Now back to the issue. The problem I see with your proposed solution is that I believe the fitting you are using is pipe thread and you have it screwed into straight threads on the MC. I don't believe this will work. I have seen others connect up the proper way so I know it is doable. Too bad none of them have provided any pictures or insight.
Have you spoken with anyone at ANPlumbing.com? One of the reasons I use that vendor is because they have people there that will work with you and get you what you need. Prices are pretty close to Summit and Jegs but their searchability is much better. Maybe a lower profile banjo/bolt will work...maybe not, but it might be worth a phone call to ask what they have available?
Then, of course, there is always frame member modification...if you are willing and able. I seem to remember a small modification was done on the other setups I saw with the tubes coming out the front.
Crash, I do like the banjo fittings. I could definitely use them for the MC's, you don't have to buy them from me lol.
Here is the link to the elbow fitting I got. It's 3AN female to 3AN male:
Podavelle 3AN Female to 3AN Male Flare 90 Degree Elbow Swivel Fitting Adapter Coupler Aluminum Black https://a.co/d/6IZjW98
Let me know what you think. Also, I'm thinking about getting more banjo fitting for the other MC's. They just seem very reliable.
Last edited by ohmygosuness; 04-25-2023 at 02:14 PM.
I am aware of an early build that used the C5 power steering rack, but 99% use the manual rack from FFR.
Hi Beeman. Yes, I do have the manual rack from FFR installed. So, I don't think there's a need for the power steering pump. I was wondering if I need an aftermarket belt or a power steering delete bracket to make this work.
Last edited by ohmygosuness; 02-20-2023 at 02:55 PM.
I went and looked at the Tilton catalog and this is listed for use in the reservoir side. Thread is 9/16 18, probably too large, but very low profile, made out of steel, so I wouldn't worry about high pressures, but I would change the orings out for copper washers.
Hot water on driver's side under rocker panel and cool side on passenger side.
It does require quite a few 90 degree and 45 degree both soft and hard bends. I also have the advantage of having a tube beader so I cut to length and then beaded the ends of the tubes.
I did every connection with double hose clamps for two reasons:
1) It is a rule requirement for the racing sanctioning bodies we run under
2) I also used a 30 pound cap that allows me to run the cooling system to 250 degrees without boil over
Double hose clamps is not a big deal if you have the normal 4 hose connections. 8 versus 4 hose clamps used. But when you have a GTM...holy crap I ordered fifty 1.5" and fifty 1.75" clamps. I used 10 silicone elbows on each side so two ends equals 20 single hose clamp connections, equals 40 double hose clamp connections!
If you are just running a street GTM you can use regular rubber elbows and single hose clamps. It is a bit of work though. Just be prepared.
I will note that the fuel tanks are not in the stock location on this race car. I know people have done the conversion to outside lines with the stock fuel tanks, but I am not sure how they ran the water lines around them. I would think the hot would be easy to go over the drivers tank and then down to the rocker area. The cool line I am not sure how that was done on a stock GTM. Maybe someone that has done it can share?
Hot water on driver's side under rocker panel and cool side on passenger side.
It does require quite a few 90 degree and 45 degree both soft and hard bends. I also have the advantage of having a tube beader so I cut to length and then beaded the ends of the tubes.
I did every connection with double hose clamps for two reasons:
1) It is a rule requirement for the racing sanctioning bodies we run under
2) I also used a 30 pound cap that allows me to run the cooling system to 250 degrees without boil over
Double hose clamps is not a big deal if you have the normal 4 hose connections. 8 versus 4 hose clamps used. But when you have a GTM...holy crap I ordered fifty 1.5" and fifty 1.75" clamps. I used 10 silicone elbows on each side so two ends equals 20 single hose clamp connections, equals 40 double hose clamp connections!
If you are just running a street GTM you can use regular rubber elbows and single hose clamps. It is a bit of work though. Just be prepared.
I will note that the fuel tanks are not in the stock location on this race car. I know people have done the conversion to outside lines with the stock fuel tanks, but I am not sure how they ran the water lines around them. I would think the hot would be easy to go over the drivers tank and then down to the rocker area. The cool line I am not sure how that was done on a stock GTM. Maybe someone that has done it can share?
I've been wondering if it's outside (or under the car) what happens if it hits a rock on the highway. My car may see some tracks but it's mainly for the streets, and the roads in Houston are VERY bumpy.
You should not have to change any frame components. We did not.
The tubes are still very much enclosed, just not in the drivers compartment.
They go in the area where the rocker panels are, just outside the frame on each side.
You may note that the next car that FFR built, the 818, the cooling tubes were kept outside the driver's compartment and run along the sides of the car.
The only drawback that we saw to moving these out to the sides was that the tubes are more exposed to an impact in any potential side impact incident. They are VERY low, especially compared to other street car bumper heights, and so this doesn't seem like it is that big of a concern.
Yes, that is what I meant by a "single flare". It is referred to as a single flare because when you are making a flare on the end of a tube, it is the first step of a two step process to make an "inverted flare". The "bubble flare" or "single flare" is known to not be able to hold as much pressure or nut tightening force, so the "double flare" or "inverted flare"(same thing) is most commonly used. A single or bubble flare should work though, as long as there is a seat on the MC for the bubble to mate to?
I believe the Corvette runs what is termed a "reverse" system. In other words the cool water is at the thermostat and the hot water comes from the port at the top of the pump.
All of the belt/relocation brackets should be included with the GTM kit to mount the alternator and install the donor belt tensioner. The other options are to use the Cadillac CTS-V alternator mount instead of the FFR mount since the FFR mount is not great. I also offer a belt tensioner kit that replaces the FFR bracket....which, once again, isn't great but can work.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
All of the belt/relocation brackets should be included with the GTM kit to mount the alternator and install the donor belt tensioner. The other options are to use the Cadillac CTS-V alternator mount instead of the FFR mount since the FFR mount is not great. I also offer a belt tensioner kit that replaces the FFR bracket....which, once again, isn't great but can work.
Sometimes I'm just waiting for orders to come in and I'll be day dreaming about how am I going to put everything together on the engine. I may be thinking way ahead of myself. Thanks for letting me know that they provide a bracket in the kit to adjust the belt.
I just noticed I'll need a C5 AC bracket as well as a C5 AC compressor. I just have them ordered, currently waiting for them to come in before I start thinking about dropping in.
What's wrong with the FFR alternator relocation bracket?
Hands down the best setup is the CTS-V Alternator and bracket with Shane's belt tensioner. Especially if you are going with a bit higher HP.
Make sure you get the right alternator as Cadillac changed over mid year and the old one needs a PWM signal to turn on and that's the one I got as I can control the output voltage with my ECU. There are a few large threads on the other forum with details you can read up on.
Hands down the best setup is the CTS-V Alternator and bracket with Shane's belt tensioner. Especially if you are going with a bit higher HP.
Make sure you get the right alternator as Cadillac changed over mid year and the old one needs a PWM signal to turn on and that's the one I got as I can control the output voltage with my ECU. There are a few large threads on the other forum with details you can read up on.
I'm assuming the main reason to use CTS-V alternator is for the voltage output adjustment?
Currently the engine is a stock LS2, should be making around 400 HP. I do have plans to make a bit more power, with something along the lines of AWD. I'll definitely look into the CTS-V. Still waiting for the C5 AC compressor/bracket to come in, so I can install it before dropping the engine in.
What I might be worried about is that I try to avoid having solid elements at 90 degrees to a screwed in element because this gives leverage to allow the screwed in element to be unscrewed. Does that make sense? Just curious...why not use the "bubble flare" like you discussed previously?
What I might be worried about is that I try to avoid having solid elements at 90 degrees to a screwed in element because this gives leverage to allow the screwed in element to be unscrewed. Does that make sense? Just curious...why not use the "bubble flare" like you discussed previously?
That makes a lot of sense. It's actually one thing I'm worried about while putting this together.
I'm planning on using the bubble flare line on the inner-most MC. Because that's the one interfering with the frame. Other 2 MC (middle and far right) will have a banjo.
I may have to come up with a solution to prevent the T from unscrewing due to vibration or other effects over time...
Here is a picture before the current redo. It is really pretty straight forward. It just requires a bit of finagling around, particularly on the front, to get through the frame work and hooked up to the radiator.
Been working on the hole sticking out on the valley cover. Got a 3/8" NPT plug then tapped the oil pressure sensor hole with 5/8" threads. Screwed in the plug up-side-down so the flat end is flush with the top of the cover. The plug width (thread-to-thread) is slightly wider than 5/8", something like 21/32. This allowed me to torque the plug into the thread really tight. I was going to add epoxy to the thread to make it more permanent, but seems unnecessary. Although, I could fill the underside of the cover with epoxy just so it could be flat. valley plug.jpg plugged valley bottom.jpg plugged valley cover top.jpg
Last edited by ohmygosuness; 02-25-2023 at 08:48 PM.
Been working on the hole sticking out on the valley cover. Got a 3/8" NPT plug then tapped the oil pressure sensor hole with 5/8" threads. Screwed in the plug up-side-down so the flat end is flush with the top of the cover. The plug width (thread-to-thread) is slightly wider than 5/8", something like 21/32. This allowed me to torque the plug into the thread really tight. I was going to add epoxy to the thread to make it more permanent, but seems unnecessary. Although, I could fill the underside of the cover with epoxy just so it could be flat. valley plug.jpg plugged valley bottom.jpg plugged valley cover top.jpg
DO NOT fill the underside with epoxy. You need to be very careful with anything that is in the oil system on the engine. ANY contamination, like little bits of epoxy that might break off, can cause catastrophic engine failure. Avoid putting anything into the engine oil system after the filter that could even possibly be an issue. If the plug is tight enough I might recommend a bit of Teflon tape to make sure there are no leaks, but again, be double sure that you clean any excess off the threads before installing the cover. This is critical.
DO NOT fill the underside with epoxy. You need to be very careful with anything that is in the oil system on the engine. ANY contamination, like little bits of epoxy that might break off, can cause catastrophic engine failure. Avoid putting anything into the engine oil system after the filter that could even possibly be an issue. If the plug is tight enough I might recommend a bit of Teflon tape to make sure there are no leaks, but again, be double sure that you clean any excess off the threads before installing the cover. This is critical.
Noted. No epoxy. I do have Teflon tape, I'll probably try that instead. Thanks.
Man, am I glad I posted it on here before trying something stupid
Last edited by ohmygosuness; 02-27-2023 at 11:17 AM.
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. On a serious note, the recommendations and pointers from the group are pretty solid, so feel free to ask away.
Originally Posted by Shoeless
